centos7一些基础优化
1、修改主机名的命令 hostnamectl
hostnamectl set-hostname --static alanPan
2、firewalld打开关闭防火墙与端口(active是启动状态，inactive是关闭状态)
systemctl status firewalld.service
systemctl stop firewalld.service --关闭此服务
systemctl list-unit-files |grep firewalld --查看firewalld是否开机自动启动
（1）设置开机启用防火墙：
systemctl enable firewalld.service
（2）设置开机禁用防火墙：
systemctl disable firewalld.service
（3）启动防火墙：
systemctl start firewalld
（4）关闭防火墙：
systemctl stop firewalld
（5）检查防火墙状态：
systemctl status firewalld
（6）查看防火墙状态：
firewall-cmd --state
（7）重新加载配置：
firewall-cmd --reload
（8）查看开放的端口：
firewall-cmd --list-ports
（9）开启防火墙端口：
(备注：–zone #作用域–add-port=80/tcp #添加端口，格式为：端口/通讯协议–permanent #永久生效，没有此参数重启后失效)
firewall-cmd --zone=public --add-port=80/tcp --permanent
3、关闭selinux（临时和永久关闭Selinux）
3.1临时关闭
getenforce
setenforce 0
etenforce是Linux的selinux防火墙配置命令 执行setenforce 0 表示关闭selinux防火墙。
setenforce命令是单词set（设置）和enforce(执行)连写，另一个命令getenforce可查看selinux的状态
3.2永久关闭
vim /etc/sysconfig/selinux
SELINUX=enforcing 改为 SELINUX=disabled
重启服务reboot
4、网络配置
systemctl stop NetworkManager --停止服务
systemctl status NetworkManager --查看状态，确认为关闭了
systemctl disable NetworkManager --设置为开机不自动启动
vim /etc/sysconfig/network-scripts/ifcfg-eth0xxxxx --（注意：网卡名如果不一样，自己找对应的文件）
cd /etc/sysconfig/network-scripts/
ll
5、yum配置
5.1进入yum 目录
cd /etc/yum.repos.d/
ll
-rw-r--r--. 1 root root 1664 Dec 9 2015 CentOS-Base.repo
-rw-r--r--. 1 root root 1309 Dec 9 2015 CentOS-CR.repo
-rw-r--r--. 1 root root 649 Dec 9 2015 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root 290 Dec 9 2015 CentOS-fasttrack.repo
-rw-r--r--. 1 root root 630 Dec 9 2015 CentOS-Media.repo
-rw-r--r--. 1 root root 1331 Dec 9 2015 CentOS-Sources.repo
-rw-r--r--. 1 root root 1952 Dec 9 2015 CentOS-Vault.repo
5.2 备份 yum文件
tar -zcvf yum180919.tar.gz *
-rw-r--r--. 1 root root 2060 Sep 19 03:30 yum180919.tar.gz
5.3 删除 yum 文件
[root@alanPan yum.repos.d]# rm -rf *.repo
[root@alanPan yum.repos.d]# ll
total 4
-rw-r--r--. 1 root root 2060 Sep 19 03:30 yum180919.tar.gz
5.4 新建 local.repo 文件
vim local.repo
[local]
name=local
baseurl=file:///yum
enabled=1
gpgcheck=0
5.5 配置163的centos源(cd /etc/yum.repos.d/ 在这个目录)
wget http://mirrors.163.com/.help/CentOS7-Base-163.repo
CentOS7-Base-163.repo 文件
[base]
name=CentOS-$releasever - Base - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
baseurl=http://mirrors.163.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://mirrors.163.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://mirrors.163.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - 163.com
baseurl=http://mirrors.163.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
(yum 设置有问题，后续搞定 再更新 o(￣︶￣)o)
6、时间同步
yum install ntp ntpdate --安装ntp时间同步相关软件包
下载过程中 y 就好
yum install ntp ntpdate
Loaded plugins: fastestmirror, langpacks
base | 3.6 kB 00:00:00
extras | 3.4 kB 00:00:00
updates | 3.4 kB 00:00:00
(1/4): extras/7/x86_64/primary_db | 187 kB 00:00:05
(2/4): updates/7/x86_64/primary_db | 5.2 MB 00:00:06
(3/4): base/7/x86_64/group_gz | 166 kB 00:00:06
(4/4): base/7/x86_64/primary_db | 5.9 MB 00:00:07
Determining fastest mirrors
* base: mirrors.aliyun.com
* extras: mirrors.cn99.com
* updates: mirrors.cn99.com
Resolving Dependencies
--> Running transaction check
---> Package ntp.x86_64 0:4.2.6p5-22.el7.centos will be updated
---> Package ntp.x86_64 0:4.2.6p5-28.el7.centos will be an update
--> Processing Dependency: libcrypto.so.10(OPENSSL_1.0.2)(64bit) for package: ntp-4.2.6p5-28.el7.centos.x86_64
---> Package ntpdate.x86_64 0:4.2.6p5-22.el7.centos will be updated
---> Package ntpdate.x86_64 0:4.2.6p5-28.el7.centos will be an update
--> Running transaction check
---> Package openssl-libs.x86_64 1:1.0.1e-42.el7.9 will be updated
--> Processing Dependency: openssl-libs(x86-64) = 1:1.0.1e-42.el7.9 for package: 1:openssl-1.0.1e-42.el7.9.x86_64
---> Package openssl-libs.x86_64 1:1.0.2k-12.el7 will be an update
--> Running transaction check
---> Package openssl.x86_64 1:1.0.1e-42.el7.9 will be updated
---> Package openssl.x86_64 1:1.0.2k-12.el7 will be an update
--> Finished Dependency Resolution
Dependencies Resolved
==============================================================================================================================================================================================================================================================================
Package Arch Version Repository Size
==============================================================================================================================================================================================================================================================================
Updating:
ntp x86_64 4.2.6p5-28.el7.centos base 549 k
ntpdate x86_64 4.2.6p5-28.el7.centos base 86 k
Updating for dependencies:
openssl x86_64 1:1.0.2k-12.el7 base 492 k
openssl-libs x86_64 1:1.0.2k-12.el7 base 1.2 M
Transaction Summary
==============================================================================================================================================================================================================================================================================
Upgrade 2 Packages (+2 Dependent packages)
Total download size: 2.3 M
Is this ok [y/d/N]: y
Downloading packages:
No Presto metadata available for base
warning: /var/cache/yum/x86_64/7/base/packages/ntpdate-4.2.6p5-28.el7.centos.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY ] 0.0 B/s | 39 kB --:--:-- ETA
Public key for ntpdate-4.2.6p5-28.el7.centos.x86_64.rpm is not installed
(1/4): ntpdate-4.2.6p5-28.el7.centos.x86_64.rpm | 86 kB 00:00:06
(2/4): ntp-4.2.6p5-28.el7.centos.x86_64.rpm | 549 kB 00:00:07
(3/4): openssl-1.0.2k-12.el7.x86_64.rpm | 492 kB 00:00:00
(4/4): openssl-libs-1.0.2k-12.el7.x86_64.rpm | 1.2 MB 00:00:00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 306 kB/s | 2.3 MB 00:00:07
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Importing GPG key 0xF4A80EB5:
Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) "
Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5
Package : centos-release-7-2.1511.el7.centos.2.10.x86_64 (@anaconda)
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Is this ok [y/N]: y
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Updating : 1:openssl-libs-1.0.2k-12.el7.x86_64 1/8
Updating : ntpdate-4.2.6p5-28.el7.centos.x86_64 2/8
Updating : ntp-4.2.6p5-28.el7.centos.x86_64 3/8
Updating : 1:openssl-1.0.2k-12.el7.x86_64 4/8
Cleanup : ntp-4.2.6p5-22.el7.centos.x86_64 5/8
Cleanup : ntpdate-4.2.6p5-22.el7.centos.x86_64 6/8
Cleanup : 1:openssl-1.0.1e-42.el7.9.x86_64 7/8
Cleanup : 1:openssl-libs-1.0.1e-42.el7.9.x86_64 8/8
Verifying : ntpdate-4.2.6p5-28.el7.centos.x86_64 1/8
Verifying : ntp-4.2.6p5-28.el7.centos.x86_64 2/8
Verifying : 1:openssl-1.0.2k-12.el7.x86_64 3/8
Verifying : 1:openssl-libs-1.0.2k-12.el7.x86_64 4/8
Verifying : 1:openssl-libs-1.0.1e-42.el7.9.x86_64 5/8
Verifying : ntp-4.2.6p5-22.el7.centos.x86_64 6/8
Verifying : ntpdate-4.2.6p5-22.el7.centos.x86_64 7/8
Verifying : 1:openssl-1.0.1e-42.el7.9.x86_64 8/8
Updated:
ntp.x86_64 0:4.2.6p5-28.el7.centos ntpdate.x86_64 0:4.2.6p5-28.el7.centos
Dependency Updated:
openssl.x86_64 1:1.0.2k-12.el7 openssl-libs.x86_64 1:1.0.2k-12.el7
Complete!
[root@localhost yum.repos.d]#
vim /etc/ntp.conf --确认配置文件里有下列的时间同步源
server 0.centos.pool.ntp.org iburst
server 1.centos.pool.ntp.org iburst
server 2.centos.pool.ntp.org iburst
server 3.centos.pool.ntp.org iburst
systemctl enable ntpd --设置开机自动启动ntpd
systemctl start ntpd --立即启动ntpd服务
systemctl enable ntpd
Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.
[root@localhost yum.repos.d]# systemctl start ntpd
[root@localhost yum.repos.d]#
7、命令的参数可以自动补全
yum install bash-completion
8、设置默认启动级别为图形模式（相当于以前的5级别)
systemctl get-default --查看当前的运行模式
systemctl set-default graphical.target --设置图形模式为默认模式
systemctl set-default multi-user.target --设置命令行模式为默认模式
[root@localhost yum.repos.d]# clear
[root@localhost yum.repos.d]# systemctl get-default
graphical.target
[root@localhost yum.repos.d]# systemctl set-default multi-user.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/multi-user.target.
[root@localhost yum.repos.d]#
